The present invention generally relates to optical elements, such as ophthalmic elements, comprising a substrate, a compatiblizing coating and a functional organic coating on at least a portion of a surface of the substrate. The present invention also relates to compatiblizing coating compositions that may be used to form compatiblizing coatings on the surface of an optical element, and methods of making optical elements comprising compatiblizing coatings.
Optical elements, such as, for example, ophthalmic elements, may be adapted for use in certain applications by applying one or more functional organic coatings to the element. For example, it is possible to adapt an optical element, such as an ophthalmic element, for use in photochromic eyewear applications by applying a photochromic coating to the surface of the element. Ophthalmic elements with photochromic coatings, such as photochromic lenses for eyewear applications, can provide the wearer with an appropriate level of transmitted radiation depending upon the ambient conditions.
Further, it is possible to adapt an optical element, such as, an ophthalmic element, for use in polarizing applications by forming a polarizing coating that comprises an aligned liquid crystal material and a dichroic dye on the surface of the element. Ophthalmic elements with polarizing coatings, such as polarizing lenses for eyewear applications, can provide the wearer with reduced reflected light glare by linearly polarizing some percentage of the radiation transmitted through the element.
It is also possible to adapt an optical element to display both photochromic and dichroic properties under certain conditions by forming a coating comprising an aligned liquid crystal material and a photochromic-dichroic dye on the surface of the element. Optical elements with photochromic-dichroic coatings may switch from a first state, for example, a clear, non-polarizing state, to a second state, for example, a colored, polarizing state, in response to actinic radiation, and may revert back to the first state in the absence of actinic radiation and in response to thermal energy. For example, ophthalmic elements with photochromic-dichroic coatings, such as lenses for eyewear applications, may transition between a clear, non-polarizing state and a colored, polarizing state to provide the wearer with both an appropriate level of transmitted radiation and reduced reflected light glare depending upon the ambient conditions.
However, if the interaction between the functional organic coating and the surface to which it is applied is insufficient, the functional organic coating (or portions thereof) may not properly adhere to the surface. For example, if a liquid crystal coating (such as those discussed above) and the substrate surface lack sufficient compatibility, the coating may not property adhere to the surface and may be easily removed from the surface, for example, by peeling. In the context of lenses for ophthalmic applications, peeling of the polarizing coating from the surface of the lens will degrade the overall performance of the lens by permitting unpolarized light to pass through those portions of the lens from which the coating has been removed.
It is possible to apply a compatiblizing coating to the surface of a substrate to improve compatibility between the substrate and a photochromic coating applied thereto. However, the compatiblizing coating that is used in conjunction with one coating/surface combination may not provide adequate compatibility between the same surface and a different coating. Thus, different coating/surface combinations may require the use of different compatiblizing coatings.
The need to use different compatiblizing coatings in connection with different coating/surface combinations, however, may lead to, among other things, manufacturing inefficiencies and increased costs. Accordingly, it would be advantageous to develop compatiblizing coatings that may be used to enhance the compatibility of a variety of coating/surface combinations to provide satisfactory compatibility between the coatings and the surfaces.